Many technologies that utilize the shape and motion of a user's fingers to control a device have already been proposed. For example, Patent Literature 1 describes a technology that estimates a hand shape from image data captured by a camera. Also, Patent Literature 2 describes a technology that estimates a hand shape by radiating infrared light from a light source disposed in a wrist area, sensing reflections of the infrared light off the fingers with an infrared camera (imager), and performing image recognition. Also, Patent Literature 3 describes a technology that uses a method such as holding up a hand to a camera and causing particular speech to be recognized to present an intention to input to an equipment side, and start a recognition process. According to the above, when a hand is moved unexpectedly, the misrecognition of a gesture and the execution of an unintended command are prevented. Patent Literature 4 describes a technology that detects an amount of finger curl by wearing a glove with a built-in sensor on the hand.